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ISL29501-ST-EV1Z Evaluation Board Manual
1.
Functional Description
The ISL29501-ST-EV1Z is both a reference design and evaluation board that provides a single platform to
evaluate the features of the ISL29501. The ISL29501-ST-EV1Z circuit board and supplied enclosure deliver
maximum electrical and optical performance.
The system sends out light pulses through the emitter LED and receives returned light pulses that reflected off a
target. The difference in phase of the emitted signal and the return signal is converted to distance by the ISL29501
and is graphed in the evaluation software. The magnitude of the return signal is graphed as well. This and
additional data is available in chip registers, see UG054, ISL29501 Evaluation Software Manual for additional
details.
1.1
Operating Features
The ISL29501-ST-EV1Z evaluation board is shown in
controlled by a software switch, which can be overridden shorting J9 pins 1 and 2. See the schematic for details. A
Power-Good (PG) LED indicates that the LDO is regulating properly.
1.1.1
External Power Supply
For high current/high duty cycle setups, USB power may not be able to power the board. In the default condition,
jumper J10 shorts pins 1 and 2 to connect to USB power to the LDO. To power the board with an external power
supply, remove this jumper and connect the positive (+) terminal to J10-2 and the negative (-) to J10-4.
If you want to bypass the LDO and power the ISL29501 directly with a power supply, remove the jumper on J10.
Use J10-4 for your ground connection and apply the positive voltage to TP7.
1.1.2
External Microprocessor
For debug of customer written software, it might be useful to connect the Sand Tiger to a different microprocessor.
2
The I
C pins SCL and SDA are available on pins J4-4 and J4-3, respectively. The remaining support pins are
available on J5: SS - J5-4, IRQ - J5-3, and CEn - J5-2. The support pins are generally connected to GP pins on
the microprocessor. SCL and SCL are compatible with 1.8V microprocessors but unfortunately the support pins
require 3V signaling.
1.1.3
System Calibration
Before meaningful measurements can be made, the calibration registers in the chip need to be loaded. This can
be done in two ways. The first is to load a profile that contains data into the GUI. This could be one of the Renesas
provided profiles or one that was saved previously by the user. See UG054, ISL29501 Evaluation Software
Manual for further details. The second is to calibrate the board directly.
1.1.4
Calibrating Sand Tiger
There are three separate standard calibrations that need to be executed to calibrate the system. These are
magnitude, crosstalk, and distance calibrations.
1.1.4.1
Magnitude Calibration
Magnitude calibration is done after the emitter current and duty cycle settings are programmed. It is a dark (no
light) calibration that takes less than 1s to run. Run this calibration from the GUI.
1.1.4.2
Crosstalk calibration
Crosstalk is defined as a signal that reaches the ISL29501 chip directly without bouncing off the target. This can
be electrical or optical. At close range and large return signal values, crosstalk has a minor impact on distance
measurements. At the far end of the distance range, the crosstalk might exceed the signal, adding error to
measurements.
UG055 Rev.1.00
Apr 5, 2022
Figure 4
and
Figure
5. The hardware enable function is
Page 3
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